HDR plugin to automatically create EXR file. For VFX use

Hi all,

I created a new plugin. It takes a series of bracked pictures and merges them one HDR exr file.
Main use would be for on set vfx shoots.
You just plant the camera, push the button, run away, wait (30 sec for all the pics, 1 min for the merge) and download the exr.

It measures the middle lighting situation and bases the other pictures of the bracket on that. It takes 2 stop increases. It tries to keep the iso as low as possible but also the exposure time, when exposure gets above 1 sec, it increases iso (until it runs out of iso and then increases exposure time again :wink: .)

See https://github.com/iamagod/HDR2EXR for the files etc.

Enjoy, let me know what you think!


Feel free to change, improve and of course use!

Greetings Kasper


this is incredible!!

Fantastic contribution, thank you!

Installed and tested, added some comments here:


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It’ll be easier to find the comments about HDR2EXR if we continue the discussion on this topic. I moved some of the testing posts to this topic. I’m also going to add a tag for HDR to this topic.

This is so exciting! Really nice work @Kasper. It works exactly like you describe it. Your README is really clear and easy to use, thanks for putting in all the details.

  1. Installed easily
  2. Took bracketed pictures easily. Building the EXR file takes about one minute, like you state in the README, and the extra LED and audio clues make it nice and clear.
  3. I can see all 11 jpg images
  4. The EXR file is 160MB


One thing I noticed for people working on a Mac. If you like a GUI and were thinking it’s easier to use RICOH THETA File Transfer for Mac than adb, you’ll have troubles. The .exr file will not show up.

In adb, it shows up clearly. (Click on the image to get a larger version.)

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@jcasman Did you try opening the file in GIMP? Opened up on Linux with the newest version of GIMP.

It may be more meaningful to test the file in Maya, Blender, or even Unity. I have only used the exr file from the plug-in in GIMP. If you have a nice scene that you used for the EXR file, please send it to me. Something outdoor with light and dark would be good. I’ll try out some of the lighting techniques tomorrow.

This plug-in is a massive improvement to the workflow.

If you want to try Blender, or Maya, check out these tutorials.




Updated to GIMP 2.10.8 which includes EXR plugins and it’s no problem to see the .exr file now.

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This is the compiled apk that @jcasman and I are using for testing.


Currently, your camera must be in Developer Mode. This is free, but you must apply for the Ricoh Plug-in Partner Program.

You must have android platform-tools adb installed on your computer and it must be in your executable PATH.

  1. download apk to your local computer
  2. connect computer and THETA V with USB cable
  3. adb install hdr-plugin.apk
  4. using Vysor, set permissions


  1. Use RICOH desktop app to set HDR4EXR as the default plug-in to boot

Usage from the README

How to use?

  1. Start the plugin by holding down the mode button for 2 seconds. The little led will turn white. And the wifi logo will blink in Magenta.

  2. Put the camera on chosen location (use a tripod, shooting handheld will lead to crappy pictures) and push photo button. You have 3 seconds to run away and hide, else you are in the picture. (Will probably increase this to 5 sec.)

  3. The Wifi logo turns greens and the theta makes picture taking sounds. It takes 12 pictures (1 to measure lighting 11 brackets).

  4. After the picture taking the wifi logo will turn blue. You can now move or pick up the camera. It is busy merging the pictures. This takes about a minute. When it is done it makes a sound and the wifi logo turn magenta again.

  5. Connect camera to a computer to download the pictures.

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Hi @codetricity and @jcasman,

Thanx for the enthusiastic response!

I usually use nuke from the foundry for exr checking. You can get a non-commercial version (works up to HD) for free. See https://www.foundry.com Also Fusion (now part of davince resolve) is very good and free tool to check the pictures. Both are hardcore vfx compositing tools.

@jcasman the problem with the theta file viewer is that the device probably was still busy. As the names of the jpg’s also wasn’t their final names. I think if you check again now it all should look good.

Two things I ran into today.

  1. after going through the whole process of creating 1 exr and then right after that creating another one (without restart or anything) I had some errors on the second run. So I will look into that.

  2. I had some very bright exr’s when shooting in daylight (all my tested where done in the evening :wink: ) so right now I’m looking into doing some form of tonemapping to make the exr look a bit better. I will keep you posted.

I will also add some stuff to the readme on github. I will start the work on the tutorial about openCV soon.

Talk to you soon!

Greeting Kasper


@Kasper Thanks for the extra info!

  • Not sure about the THETA file viewer. It still does not show the .exr file, even after waiting. This is not critical, since I think adb is a better tool here anyway.

  • Just adding a comment that the .exr created by the plug-in appeared quite bright. The THETA was placed pretty close to a big bay window with lots of sunlight. To be clear, I’m not saying it needs to be changed. I’m just noticing what the .exr image looked like when I opened it up in GIMP.

I can replicate these two issues.

I signed up with Foundry for Nuke, non-commercial. I think I need to wait for a human being to check my application. I’m going to use Blender while I wait.

This is a really interesting project and @jcasman and I are working on some end-user articles that we’ll contribute to your project:

  • install
  • usage
  • basic lighting test
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We’ve started working on some intro documentation to help others get up and going. If a developer is already comfortable with installing an apk and using Vysor to set permissions, that’s great. I think it’s already very accessible, based on my own testing. But I’m hoping to extend it out to “power users” who don’t consider themselves developers but who are perfectly capable of taking 10-15 minutes to use adb and and Vysor and install an apk in their THETA for the first time and try it out. In VFX, I would think there are a fair amount of users like that.

We’ve forked your repo and have started building the documentation here:


It needs more work, but it’s a start. We are planning to do a PR so you can include the documentation in your repo if you want. Please expect that this week.

And! To make it even easier for people who don’t want to use adb and Vysor you should consider submitting it to the THETA Plug-in Store! Then even people without an unlocked THETA V can download it and install it easily and try it out.

I’ve done this a couple of times, it takes a couple rounds of submitting, I’d be willing to help, to take on a big chunk of the effort if you’re interested.

Let me know! The VFX world is waiting!


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FYI, here’s a note from roohii_3 about HDR2EXR - original comment in Japanese

Thank you for the information. I am very happy that the article was of use.
I would like to try HDR2EXR sample as well.

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I have been searching the world over for a better HDR app for the V. I have not found anything, so I have been experimenting with completely manual brackets and then HDR merging.

This looks exciting, but I am clueless with github and clueless on where to start, even after reading this post over a few times. Is there a beginners plan somewhere that I could follow?


@FunN4Lo I can probably help. You have a THETA V? Since the apk is not in the Plug-in Store, it makes it slightly more complicated. But still do-able! First of all, you need to be able to put your THETA V in developer mode. Have you done this? If not

  1. Go here to register: https://api.ricoh/products/theta-plugin/
  2. You’ll set up a username and password and answer a few questions and then will have to upload a picture of you THETA V serial number on the bottom of the camera.
  3. Then wait.

If you get that far, let me know. I can help you with the next steps.


Thanks for the follow up. Yes, I have the Theta V. I was reading between the lines, that I had to start someplace else. :grinning:

I will follow up a bit later and post back

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We’re talking to @Kasper about getting this up into the THETA Store, which is free to put in there. One potential issue is that there is no way to charge for the app. I’m not sure if he wants to charge a small fee or not.

One option could be to use something like Patreon to give people the option of making a small donation.

Again, I don’t know if he has a business model planned for this in the future. I’m just speculating.

Right now, it is free to use.

I am going to try to figure out if I can get this to work. But I would be happy to pay for a great HDR app

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Please post any problems you have with the installation here. As the plug-in is not in the store, the process is fairly tough. Once the plug-in is installed, it functions the same as a plug-in the store. Just put it into plug-in mode and press the shutter button.

Again, the developer has generously put this out as open source and we can all enjoy it. Thank you to @Kasper.

I’m just speculating on a future commercial version in the store because I think there is a market for it. I also think that selling it and getting small amounts of money is a good way to keep motivated to add features to the plug-in.

It’s a really great plug-in app and I think that people will use it. I’m sure they will want features. It’s a massive improvement to the workflow as you don’t need to bring out the mobile phone for each HDR scene.

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Hi @codetricity and @jcasman,

Putting the app in the plugin store is a great idea. Definitly something we need to do. I don’t want any money or anything for it. Just want people to use it!

Only thing that is for now holding me back is that I am not 100% happy with the quality of the outputted merged HDR exr file. I’ve done a couple of test shots in bright daylight and the pixel values go way through the roof (2500 and even higher). Values above 1 are allowed but this is to much also considring that many of the pixels are this high. So I’ve been testing some solutions, mainly divinding all the pixels bij the mean value of the whole image. This works pretty well so far but I want to do a bit more testing. Also I have some indoor night shots with weird red values which I want to look at.

In the mean time I fixed the problem with doing a second pass without turning the camera off. That should be fixed and I merged that on github with the master branch.

Also I think adding a webinterface can be a great addition but maybe we should save that for version 2.

Thanx for the PR work and everything!

I’ll keep you posted!